title: Development and characteristics of preclinical experimental models for the research of rare neuroendocrine bladder cancer.
abstract: OBJECTIVE
  For rare cancers such as neuroendocrine bladder cancer treatment options are limited due partly to the lack of preclinical models. Techniques to amplify rare primary neuroendocrine bladder cancer cells could provide novel tools for the discovery of drug and diagnostic targets. We developed preclinical experimental models for neuroendocrine bladder cancer.
  
  
  METHODS
  Fresh tumor tissue from 2 patients with neuroendocrine bladder cancer was used to establish in vitro and in vivo models. We analyzed additional archived tissues in the National Center of Tumor Diseases tissue bank from patients with neuroendocrine bladder cancer. Primary tumor samples were collected during radical cystectomy. PHA-665752 was used to inhibit MET in animal models and cell cultures. The expression of markers and drug targets in neuroendocrine bladder cancer was determined by flow cytometry. The growth of neuroendocrine bladder cancer in vitro was determined by counting live cells. Tumor growth in mice was assessed by measuring tumor volume. Groups were compared using the nonparametric Kruskal-Wallis test.
  
  
  RESULTS
  Xenograft models and serum-free cultures of neuroendocrine bladder cancer cells allowed screening for cell surface markers and drug targets. We found expression of the HGF receptor MET in neuroendocrine bladder cancer cultures, xenograft models and primary patient sections. The growth of neuroendocrine bladder cancer spheroids in vitro depended critically on HGF. Treatment of neuroendocrine bladder cancer bearing mice with a MET inhibitor significantly decreased tumor growth compared to that in control treated mice.
  
  
  CONCLUSIONS
  Neuroendocrine bladder cancer xenografts and serum-free cultures provided suitable models in which to identify diagnostic markers and therapeutic targets. Using the models, we noted HGF dependent growth of human neuroendocrine bladder cancer and identified MET as a new treatment target for neuroendocrine bladder cancer.
authors.affiliation: Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), German Cancer Research Center, Heidelberg, Germany; Department of Urology, University Hospital Heidelberg, Heidelberg, Germany. Electronic address: thomas.hoefner@hi-stem.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofner
authors.forename: Stephan
authors.initials: S
authors.lastname: Macher-Goeppinger
authors.forename: Corinna
authors.initials: C
authors.lastname: Klein
authors.forename: Teresa
authors.initials: T
authors.lastname: Rigo-Watermeier
authors.forename: Christian
authors.initials: C
authors.lastname: Eisen
authors.forename: Sascha
authors.initials: S
authors.lastname: Pahernik
authors.forename: Markus
authors.initials: M
authors.lastname: Hohenfellner
authors.forename: Andreas
authors.initials: A
authors.lastname: Trumpp
authors.forename: Martin R
authors.initials: MR
authors.lastname: Sprick
mesh_terms: D000818:Animals; D035843:Biomedical Research / Q000379:methods; D004195:Disease Models, Animal; D064593:Heterografts; D006801:Humans; D051379:Mice; D009368:Neoplasm Transplantation; D018358:Neuroendocrine Tumors; D000090063:Proto-Oncogene Mas; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms
keywords: BC; DMSO; FACS; FITC; HGF; HGF protein; NEBC; NOD.Cg-Prkdcscid IL2rgtm1Wjil; NSG; RC; animal; bladder cancer; carcinoma; dimethyl sulfoxide; disease models; flow cytometry; fluorescein isothiocyanate; hepatocyte growth factor; human; neuroendocrine; neuroendocrine bladder cancer; proto-oncogene proteins c-met; radical cystectomy; urinary bladder